1. Field of the Invention
The present invention relates to a flocculating agent. More particularly, it relates to a cationic polymer flocculating agent having an amidine structural unit.
2. Prior Arts
Cationic polymers are used in such applications as flocculating agents, paper-treating agents, and the like. Conventionally known cationic polymers include polymers of metal or ammonium salts of dialkylaminoalkyl(meth)acrylates, and Hofmann degradation or Mannich reaction products of polyacrylamides. Recently, polyvinylamines obtained by partially modifying homo- or copolymers of N-vinylformamide have been proposed in U.S. Pat. Nos. 4,421,602, 4,774,285 and 4,957,977.
However, the conventional cationic polymers have some disadvantages in certain applications; for example, dehydrating properties, filterability and stability upon storage are still insufficient when used as flocculating agents. Thus, there is a need for further improvement in the performance of cationic polymers.